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1.
中华硬蜱唾液腺抗原成分的分析研究 总被引：8，自引：0，他引：8
中华硬蜱唾液腺提取物（ＳＧＥ）经ＳＤＳ聚丙烯酰胺凝胶电泳显示出２４条蛋白带，其中主带有６条，分子量分别为１４２、１０５、９４、６６、６４和５６ＫＤ。用中华硬蜱叮刺家兔后血清做免疫印渍，特异性抗原带为１０５和９４ＫＤ。说明中华硬蜱１０５和９４ＫＤ的蜱唾液腺蛋白原能够有效地诱慢宿主产生抗体。 相似文献
2.
杨树和柳树均属于杨柳科植物,两者在经济林及绿化行道树上的运用越来越广泛。锈病在杨树和柳树高栽植密度苗圃地和成片用材林的发生极为严重。本研究比较杨树和柳树锈病的发病症状、流行特点及病原菌特征,为该病的防治提供理论和实际指导依据。以川东北地区4区(县)(南充市高坪区和西充县,广安市前锋区和武胜县)患发锈病的杨树和柳树为研究对象,采用流行病学调查和显微观察技术等方法。杨树锈病和柳树锈病大都侵害叶和幼苗,引起树叶早期脱落,幼苗枯萎。但杨树锈病的病原菌为锈菌科栅锈菌属松杨栅锈菌(Melampsora larici-populins),柳树锈病的病原菌为锈菌科栅锈菌属拟鞘锈栅锈菌(Melampsora coleosporioides Diet.)。杨树锈病和柳树锈病虽有共同的发病特征,但在为害症状、病原类型和发生规律方面均有很大的不同。建议在防治时根据寄主的不同选择针对性强的防治方法。 相似文献
3.
Ojimelukwe P.C. Onweluzo J.C. Okechukwu E. 《Plant foods for human nutrition (Dordrecht, Netherlands)》1999,53(4):321-332
Two cowpea varieties (Ife-brown and Kano-white varieties) were used for the study. The effects of insect infestation on the chemical composition and physicochemical properties of these cowpea seeds were studied. The proximate composition, mineral content, total starch, total soluble sugars, bulk density, fat and water absorption capacities, viscosity, gelation capacity and emulsion properties of infested cowpea varieties were compared with those of uninfested cowpeas. Effects of infestation on nitrogen solubulity and on the protein fractions were also determined. lnfestation depleted the protein, starch and soluble sugar contents of cowpeas. Oil and water absorption capacities were increased while emulsification, foam and viscosity properties were reduced. The nitrogen solubility pattern was altered. Uninfested Kano-white cowpeas (UKW) possessed better foam properties than uninfested Ife-brown cowpeas (UFB). On the other hand, UFB had better emulsification properties than UKW. 相似文献
4.
盐城农区甜菜夜蛾的灾变规律与监控新技术研究 总被引：1，自引：0，他引：1
从发生世代与年生活史、适生寄主与嗜好程度、暴发频率与为害程度、发生特点与区域分布、生物学特性与生活习性等角度综合分析了盐城农区甜菜夜蛾的灾变规律;研究总结出外来虫源是造成暴发的主要因素之一,种植结构调整有利于该虫的暴发,夏季干旱少雨为暴发创造了气候条件,频繁使用农药导致该虫的抗药性增加,田间管理粗放营造了暴发的环境条件等影响甜菜夜蛾发生消长的主要因素;提出以搞好农业防治为基础,加强预测预报为前提,狠抓化学防治为重点,利用性诱剂、灯光诱杀、人工捕捉为辅助手段,应用“主攻3代,压前控后”的防治策略等本农区甜菜夜蛾监控新技术。 相似文献
5.
The effect of different application levels of phosphate fertilizer on cowpea pod-sucking bugs [Clavigralla sp., Riptortus sp., Anoplocnemis., Mirperus sp. and Negara sp. (Heteroptera)] was studied using 0 (control), 20, 40 and 60 kg/ha of single super-phosphate. The results showed that the bug densities decreased significantly with increase in rate of application. At 40 and 60 kg/ha, grain yields were significantly higher than at the lower rates of application. Crude protein, fibre, oxalate, phytin, potassium and magnesium contents as well as seed hardness also increased with increase in the rate of fertilizer application. 相似文献
6.
阿鲁加姆锡兰蛭(Zeylanicobdella arugamensis)是重要的鱼类体外寄生虫,可感染30余种海水鱼类。阿鲁加姆锡兰蛭病在我国和东南亚多个国家的海水养殖鱼类中流行,严重时可导致鱼类大量死亡。为持续、稳定、足量地获得活体寄生虫,供防治鱼蛭病研究使用,本研究通过鱼蛭在体感染实验,建立了阿鲁加姆锡兰蛭的传代培养体系。研究结果证实,2种海水观赏鱼[棘颊雀鲷(Premnas biaculeatus)和白条双锯鱼(Amphiprion frenatus)]可作为宿主鱼,用于该鱼蛭的传代培养,且传9代后产生的子代仍具有很强的感染力。鱼蛭的生活史观察显示,该鱼蛭的生活史可分为卵茧孵化和幼蛭发育2个阶段。在水温为26℃、盐度为30的条件下,鱼蛭最短20 d即可完成其生活史。其中,卵茧孵化为幼蛭需要9 d,孵化率高达83.8%;幼蛭感染宿主、发育成熟并开始产卵茧最短需要11 d。本研究可为海水鱼蛭的生物学和鱼蛭病的防治研究提供技术支撑。 相似文献
7.
Markus Kautz Kai DworschakAxel Gruppe Reinhard Schopf 《Forest Ecology and Management》2011,262(4):598-608
Spatio-temporal dispersal of pest species such as bark beetles plays a key role in their population ecology and outbreak dynamics. Understanding the underlying patterns is crucial for applying appropriate management strategies.In contrast to most existing studies which focus on dispersing beetles, we analysed patches of killed trees resulting from bark beetle infestation. The study was based on a 22-year time series of annually captured colour-infrared (CIR) images of the Bavarian Forest National Park (Germany), where Ips typographus L. (Coleoptera, Curculionidae, Scolytinae) propagates undisturbed by human activity. Newly infested patches comprising at least 5 spruce trees were identified in every time step. This investigation of spatio-temporal spread of infestations primarily focused on (i) parameterizing the size and shape of infestation patches, (ii) modelling an infestation gradient and (iii) evaluating the risk of subsequent infestations on landscape scale. We developed a GIS-based distance ring approach to quantify the distance relation of subsequent infestations, including the distribution of potential hosts.Infestation spread was revealed to be strongly distance dependent, following an inverse power law function: on average 65% of new infestations occurred within a 100 m radius of the previous year’s infestations, and 95% within 500 m. ‘Distance’ proved to be a major determinant of I. typographus dispersal on the landscape scale in each time step of the 22-year series we investigated. Infestation distance thus describes the outcome of beetle dispersal very accurately. The time series showed two alternating periods of epidemic and non-epidemic infestation. These gradation stages did not affect the size and shape of infested patches, but epidemics correlated significantly with a higher percentage of infestations within short distances. Additionally, the resulting infestation risk is highly sensitive to the gradation stage, particularly within the first 100 m around source spots where it increases up to 30%.Our study therefore contributes to a better understanding of the outbreak dynamics of I. typographus and suggests concentrating efficient bark beetle management on areas in the close vicinity of previous years’ infestations. 相似文献
8.
土壤施肥与植食性害虫发生为害的关系 总被引：2，自引：0，他引：2
土壤施肥可以影响植物的生长和营养状况,从而影响植食性昆虫的生长发育、繁殖和为害等。在影响植物抗性和害虫为害的营养因子中,氮是一个关键的因素,氮肥对害虫发生的影响取决于害虫种类、植物种类和土壤肥力,是植物营养质量对害虫直接影响的结果,也是植物形态学、组织发育等因素的间接作用结果。很多研究表明土壤或植物中氮水平与害虫密度存在强烈正相关关系,但是也有不同情况出现。另外其他营养元素如磷和钾,也会引起害虫种群动态变化。有机管理措施可能有利于减轻害虫发生,但是机理还存在争议。 相似文献
9.
In olive orchards, which are very common in the Mediterranean region, cover crops are becoming increasingly used to counter
problems of erosion. Although such plant covers can provide food and shelter for beneficial insects, mites, and spiders, they
may also attract pests. In order to determine their relationships with the main pests in olive orchards, an analysis was made
of adult population levels and damage caused in five olive-cultivation zones, in olive orchards with cereal-crop covers and
in olive orchards with conventional tillage. The effects of the cereal cover crops on insect pest populations were different
and in some cases in opposite direction. Thus cereal cover crops had no impact on the different studied pests, including all
those that spend part of their development cycle in the soil, such as Bactrocera oleae, Prays oleae, or Otiorrhynchus cribicollis. However, under certain conditions some pests did show an increase in abundance. Diverse trophic relationships should be
investigated in this agroecosystem in future studies in order to develop appropriate crop-management policies. 相似文献
10.